This application claims the priority of German Patent Application No. 198 45 661.1, filed Oct. 5, 1998, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a protective wrapping consisting of a plastic foil for a vehicle seat as well as to a process for wrapping a vehicle seat in a protective wrapping.
During the assembly of vehicles, and also on the way from the automobile manufacturer by way of the wholesaler to the ultimate buyer, vehicle seats are repeatedly subjected to the danger of becoming dirty because workers frequently sit in the vehicle for the purpose of carrying out mounting and control work or for logistically caused drives. Thus, dirt can be brought onto the seats unnoticed by dirty work clothing or dirty hands. The situation is similar during servicing work in the customer service field.
For preventing the seats from becoming dirty during the series-type assembly of a vehicle, at least the driver seat is provided with a protective wrapping that can be used once, because this seat is used particularly frequently. In the customer service field, in addition to protective wrappings, which can be used once, protective covers are used which require higher expenditures and can be used several times. Because of the only one-time use of the wrappings, their cost should be as reasonable as possible. On the other hand, they should provide an effective and durable protection and should not slide or be damaged because of frequent entering and exiting.
One-piece protective covers are customary for this application. A continuous foil layer (i.e., a so-called front layer) is provided which covers both the seat surface and the backrest together. At the ends of the front layer, pockets are mounted which, on the top side, reach around the backrest and, on the front side, reach around the seat cushion to the backrest side or to the seat underside. For preventing or reducing the tendency of the protective cover to slide on the cushioning, strip-shaped adhesive layers are known which are glued onto the interior side (compare European Patent Document EP 457 992 B1). Additionally, the foil of the front layer is constructed as a multi-layer coextrudate, the foil layer facing the cushioning having a high coefficient of friction, and the exposed foil layer having a low coefficient of friction (compare European Patent Document EP 765 778 A2). For a better protection of the seat despite sliding, the pockets can change laterally into one another and reach around the seat also laterally in the transition area from the seat cushion to the backrest (compare DE 41 32 714 C1).
In order to permit an automated handling of the protected seats by means of an industrial robot (for gripping the seat, the robot reaches by means of a plate into the gap between the lower edge of the backrest and the seat cushion) in the area of the mentioned gap, a wider pocket is formed by means of the front layer, which pocket projects deeply into the gap. The handling tool of the robot can dip into this pocket without damaging the protective cover or directly touching the cushioning cover. Simultaneously, the pocket clamped into the gap between the backrest and the seat cushion also has the purpose of stabilizing the position of the protective cover on the seat (compare German Patent Document DE 43 33 051 C1). However, according to the applicant's experiences, this does not result in a sufficient fixing of the protective wrapping on the seat.
European Patent Document EP 564 872 B1 also states that it is known, although no sources are indicated, to shrink the cushioning parts of a vehicle seat each separately into the shrinking foil at the seat manufacturing facility before the final assembly of the seat. Although this has the advantage of an early protection and a no-slide hold of the protective foil on the cushioning and permits a robotic handling of the vehicle seats without damaging the wrapping, it is stated that this separate shrinking-in of the backrest cushion and of the seat cushion entails the risk of a condensation of trapped moisture and solvents which may result in the formation of spots and color changes in the fabric of the cover. By means of the tight wrapping of the cushioning into the plastic foil, an air exchange between the cushioning and the environment immediately after the manufacturing of the cushioning is prevented for a fairly long time so that the applicant's observations have confirmed the above-mentioned danger.
It is an object of the present invention to provide a protective covering having the following advantages: the protective wrapping should be mounted economically and at reasonable cost; it should offer an early protection and not slide when used; it should permit robotic handling of vehicle seats without the danger that the wrapping may be damaged; and there must be no risk of a formation of spots or of a local color change.
On the basis of the above-mentioned protective wrapping, this object is achieved according to the present invention. Accordingly, a separate protective covering is provided for the backrest cushion and for the seat cushion. The backrest cushion wrapping consists of a shape-adapted protective bag which loosely encloses the backrest cushion from above on all sides to the level of the seat surface. By means of a closing tongue which reaches around the backrest underside from the front to the rear, the protective bag is fixed on the backrest cushion in a secure manner with respect to sl ding. The free end of the closing tongue is glued to the rear-side foil of the backrest cushion wrapping. The seat cushion wrapping consists of a protective hood which is adapted by tailoring and which encloses the seat cushion from above on all sides. The sides are circularly gathered, particularly shrunk, below the seat cushion so that the seat cushion wrapping rests with a pre-stress laterally against the seat cushion.
The protective wrapping is formed by reasonably priced components. The wrapping of the backrest cushion is form-lockingly and securely fixed on the backrest cushion and is thus protected against sliding. The loose fit in the backrest area ensures an air exchange and avoids condensate formations on the interior side of the foil. Despite a martial shrinking-on of the seat cushion wrapping, this wrapping spans the seat surface at a distance and permits an exchange also in this case. A reaching of a robot handling system into the gap between the backrest and the seat cushion is not prevented.